title: Treatment of benzene and n-hexane mixtures in trickle-bed air biofilters.
abstract: Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 degrees C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m3 x hr). Corresponding benzene loadings ranged from 4 to 43 g/(m3 x hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios.
authors.affiliation: Environmental Engineering Program, School of Energy, Environmental, Biological, and Medical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Ashraf Aly
authors.initials: AA
authors.lastname: Hassan
authors.forename: George A
authors.initials: GA
authors.lastname: Serial
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification*; D001554:Benzene / Q000302:isolation & purification*; D002245:Carbon Dioxide / Q000032:analysis; D005374:Filtration; D005658:Fungi; D006586:Hexanes / Q000302:isolation & purification*; D055549:Volatile Organic Compounds / Q000302:isolation & purification*
chemical_list: D000393:Air Pollutants; D006586:Hexanes; D055549:Volatile Organic Compounds; D002245:Carbon Dioxide; D001554:Benzene